The present invention relates to a choke device which may be used in, for instance, two-cycle internal combustion engines.
Certain internal combustion engines, in particular, piston-valve-type two-cycle internal combustion engines, which have no valve provided in the intake system, generally experience a considerable degree of fuel blow-back and, hence, encounter various secondary drawbacks. In order to overcome this problem, an arrangement has hitherto been used in which a blow-back prevention plate is provided upstream of the suction port of a venturi of the carburetor, so as to prevent any blow-back of the fuel and to allow any fuel blown back to be sucked into the engine again. The known arrangement also has a pivotable choke valve disposed separately for the purpose of restricting the amount of air sucked at the time of engine starting.
With the known arrangement of choke devices for internal combustion engines, however, since the separate blow-back prevention plate is mounted upstream of the venturi, and the choke valve is provided separately therefrom, the entire structure of the carburetor is complicated, requires a number of parts, and calls for considerable amounts of labor and expenditure during such operations as the assembly thereof.